The objective of this research proposal is to develop technology and devices for the preservation of heart valves in the dry state. While the initial focus is on allogenic transplantation, it is the intent of the proposal to investigate the manipulation of the preservation protocol to enable heterograft transplantation. The project will initially define optimized cryopreservation and drying of intact valves. These valves will then undergo static and dynamic mechanical testing. Investigation will also be made of specific protocols designed to minimize post-implantation calcification and late failure due to valve degeneration. Once cryopreservation, drying, storage and rehydration parameters have been assessed, valves will be transplanted in the accelerated young sheep model to determine both early and late valve function and integrity. Successful application to allografts would result in convenient valve storage and transport at above-freezing temperatures (4-22oC) and following rehydration and grafting, longer life spans. Successful application to heterografts would address the major problem in current tissue heart valve transplantation--procurement.